Much has been written about the Confederate armies during the American Civil War. General Robert E. Lee's Army of Northern Virginia has gotten most of the attention of historians and writers over the years. There are several reasons for this. The Army of Northern Virginia has been identified with the Confederacy's effort for independence. Lee's army was much more successful on the battlefield than any other Confederate force. Its battles were fought near the capitals of both the North and the South, thus getting most of the attention and writing of both sides during the war. Much of the manuscript source materials on the Army of Tennessee were lost or destroyed over the years. One could also infer that writers prefer a winner over a loser.However, especially in the relatively recent past, there has been work focused on the Army of Tennessee. One such book, Two Great Rebel Armies by Richard McMurry, compares and contrasts the Army of Northern Virginia and the Army of Tennessee. In this work McMurry cites reasons he believed caused the difference in effectiveness and performance between the two armies.Additionally, there have been numerous books written about the field artillery corps of the Army of Northern Virginia. The artillerymen in the Army of Tennessee have received less attention. One recent and notable book on the subject is Cannoneers in Gray by Larry J. Daniel. However, unlike Two Great Rebel Armies, there has been no book written comparing the field artillery corps of the Army of Northern Virginia and the Army of Tennessee. Was there a difference in the effectiveness and performance of the respective field artillery corps as there was with the armies in general? If so, what were the reasons? This thesis will attempt to answer these questions.To answer these questions a look at the foundation of each army and its field artillery corps will be examined. Topics addressed in the foundation include state militia strength, equipment, and experience levels, as well as, recruiting, governmental relationships with each army, and other areas. In addition to the foundation of each force, the senior leadership of each army will be examined to determine its effect on the performance of the army and its field artillery corps. Quantity and quality of ordnance, equipment levels, logistics, and training are all important components of each armies artillery that must be examined. The effectiveness of each field artillery corps is also going to be highly influenced by its leadership, organization, and tactical use. Each of these areas will be thoroughly examined to answer the question which field artillery corps was the most productive for the Confederacy during the American Civil War.